Degradation of organic pollutants in near -neutral pH solution by Fe-C micro-electrolysis system

The degradation of organic pollutants in the simulated and realistic wastewaters was investigated by Fe C micro-electrolysis system. Effects of initial pH, Fe/C mass ratio, gas bubbling type (air or N-2) and the type of anions on degradation and mineralization of Sunset Yellow (SY) were studied. The degradation and mineralization efficiencies of 500 mg L-1 SY were approximately 99.0% and 77.5% after 90 min treatment, when the initial pH, Fe/C ratio and air bubbling flow rate were 6.0, 1:1 and 45 Lh(-1), respectively. Besides, the type of anions had a significant influence on the Fe-C micro-electrolysis process. The results of kinetics study indicated that Fe-C micro-electrolysis process followed second-order-kinetics well. The degradation pathway and mechanism for SY were proposed based on FTIR and LC-MS analyses of treated wastewater. Additionally, the Fe-C micro-electrolysis process could dispose linear alkyl chain and benzene ring compounds efficiently under the optimal conditions, and the mineralization efficiencies Were in the range of 94-96% and approximately 80%, respectively. The degradation feasibility of a realistic wastewater by the Fe-C micro-electrolysis system was investigated with landfill leachate. In conclusion, Fe-C micro-electrolysis system is an effective and promising technology for organic wastewater treatment in near-neutral pH condition. (C) 2017 Elsevier B.V. All rights reserved.